// Copyright 2024 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <cstdint>

extern "C" {
void isr_wrapper(void);
__attribute__((naked)) void isr_wrapper(void) {
  asm volatile(
      "csrr t0, mepc \n"
      "addi t0, t0, 4 \n"
      "csrw mepc, t0 \n"
      "csrr t0, mcause \n"
      "li t1, 5 \n"
      "bne t0, t1, 0f \n"
      "csrr t0, mtval \n"
      "la t1, 0xA0000000 \n"
      "bne t0, t1, 0f \n"
      ".word 0x08000073 \n"
      "0: ebreak \n"
  );
}

}  // extern "C"

int main(int argc, char** argv) {
  asm volatile("csrw mtvec, %0" :: "rK"((uint32_t)(&isr_wrapper)));
  volatile uint32_t* load_bad_addr = (uint32_t*)0xA0000000;
  volatile uint32_t foo = *load_bad_addr;
  (void)foo;
  asm volatile("ebreak");

  return 0;
}
